Circulating interleukin-6 levels and cardiovascular and all-cause mortality in the elderly population: A meta-analysis

Objective: : Inflammatory markers may be associated with mortality in the elderly population. We conducted this meta-analysis to evaluate the association of elevated circulating interleukin-6 levels with cardiovascular or all-cause mortality in the general elderly population. Methods: A comprehensive literature search was conducted through the Pubmed and Embase databases until April 2016. Prospective observational studies that investigated the association of circulating interleukin-6 levels with cardiovascular or all-cause mortality in the elderly general population (aged 60 years or more) were included. Pooled risk ratio (RR) and 95% confidence intervals (CI) were calculated by the highest vs. the lowest interleukin-6 levels. Results: Nine prospective studies involving 9087 participants were identified. When comparing the highest with the lowest interleukin-6 levels, the pooled RR of all-cause mortality and cardiovascular mortality were 1.49 (95% CI 1.33-1.67) and 1.69 (95% CI 1.27-2.25), respectively. Subgroup analysis indicated the effects of interleukin-6 on all-cause mortality were consistently observed in sample sizes, region, durations of follow-up, interleukin-6 cutoff value and number of adjusted for covariates subgroups. Conclusions: This meta-analysis indicates that elevated circulating interleukin-6 levels are independently associated with greater risk of cardiovascular and all-cause mortality in the general elderly population.